1. Field of the Invention
The invention relates to an image processing device, in particular, a technology of enabling a touch panel implemented on an operation terminal detachably held by the device to respond to a touch that the touch panel senses.
2. Background
Touch panels have now become established as input devices essential for operation of electric appliances. Indeed, touch panels are included as standard equipment in automated teller machines (ATM) of banks, and in automatic ticket machines of stations. Touch panels are standard input devices of smartphones and tablet terminals, which have spread at an explosive pace. In recent years, home electric appliances also include many types with operation panels in which touch panels are implemented.
Such widespread use of touch panels is largely due to a good operational feeling that touch panels provide to users. With touch panels, users can directly touch and operate graphic user interface (GUI) components, such as icons and virtual buttons, displayed on operation screens. The GUI components are hereinafter referred to as “gadgets.” Such easy-to-grasp operations enable the touch panels to provide users with a good operational feeling.
A known method of improving operational feeling is, for example, a technology of making a touch panel respond by light or sound to a touch that the touch panel senses. More concretely, the touch panel, when sensing the touch of a user's finger or the like, instructs the display device to change the appearance of gadgets such as their colors, shapes, and brightness, or the speaker to produce electronic sounds. Such visual or auditory response allows the user to perceive “reaction” to the touch on the touch panel, which is also called “click feeling” or “feedback,” so that the user senses that his/her operation by the touch has been accepted by the device equipped with the touch panel.
In particular, a function of a touch panel responding to a touch by vibration is referred to as “force feedback (FFB).” See, for example, JP 2006-150865, JP 2010-282346, and JP 2011-008532. By such vibration, which is hereinafter referred to as “responsive vibration,” the touch panel enables a user to feel as if the reaction to his/her touch on a virtual button were the tactile feedback from a pushed mechanical button. Since the responsive vibration is a tactile response, it can be sufficiently perceived by a user who is less able to sense change in appearance of gadgets or electronic sounds, such as a child and an elderly person.
Recently, a technology is being developed to incorporate an operation panel into a terminal portable and detachable from a device to be operated. See, for example, JP 2013-205425, JP 2014-022769, and JP 2015-143779. Such a terminal is hereinafter referred to as an “operation terminal.” An operation terminal disclosed in JP 2013-205425 is equipped with hardware similar to one built in an existing mobile electronic device such as a smartphone or a tablet, and detachably held by a device to be operated. Operation terminals disclosed in JP 2014-022769 and JP 2015-143779 are realized by existing mobile electronic devices executing specific application programs. Each of the operation terminals allows a user to handle it as a familiar, existing mobile electronic device such as his/her own smartphone. This further improves operational feeling that the touch panel built in the operation panel provides to a user.